Electrical connector



Dec. 14, 1965 R. s. RARI-:Y ETAL 3,223,963

ELECTRICAL CONNECTOR Filed may 22, 196s E E-1NVENTORS- United States Patent C) 3,223,963 ELECTRICAL CGNNECTUR Robert S. Rarey, Birmingham, Mich., and Eibert L.

`Iohnson, Warren, liio, assignors, by mesne assignments, to General Motors Corporation, Detroit, Mich.,

a corporation of Delaware Filed May 22, 1963, Ser. No. 282,445 6 Claims. (Cl. S939-259) This invention relates generally to detachable electrical connectors and more particularly to a detachable electrical terminal particularly suited for connecting an ignition cable to a spark plug for an internal combustion engine.

In the past, various designs of ignition cable terminals have been employed many of which were formed from flat metal blanks to provide, at one end thereof, a connecting portion of generally hollow cylindrical shape for circumferentially engaging the terminal of a spark plug. A generally axially extending slot, resulting from the forming operation of the connecting portion, provided a means whereby some resiliency could be experienced in the connecting portion for purposes of either connecting or disengaging the cable terminal from the spark plug terminal.

Such resilient connecting portions have not been entirely satisfactory because the tendency is to bend and permanently distort the connecting portion especially during disengagement of the cable terminal from the spark plug terminal.

Some improvements have been proposed whereby means are provided on the connecting portion for preventing undue distortion thereof. In such arrangements additional detent means may also be provided for frictionally engaging portions of the spark plug terminal in order to prevent accidental disengagement therefrom of the ignition cable terminal. In arrangements of this kind, wherein detent means are provided, desired disengagement of the ignition cable terminal from the spark plug terminal is often difficult to achieve because most, if not substantially all, of the disengaging force has to be applied axially of the ignition cable terminal. The axial direction of such a force is not always easily accomplished because of factors such as, for example, the physical location and position of the spark plugs on the engine.

Accordingly, an object of this invention is to provide in a detachable electrical connector, a connecting portion having means for securely engaging a cooperating terminal and means for enabling the disengagement of the connecting portion from said terminal by angularly displacing the connector and connecting portion with respect to said terminal.

In furtherance of the above object, the invention herein disclosed contemplates the provision, in a detachable electrical connector having a first body portion for securely engaging an electrical cable and a second generally cylindrical body portion forming an opening for the reception therein of an electrical terminal, of abutment means carried by said cylindrical body portion and directed generally inwardly of said opening for engaging said terminal when said terminal is received within said opening, said abutment means being movable relatively axially of said cylindrical body portion so as to be urged into one extreme axial position by said terminal when said terminal is being inserted into said opening and so as to be urged in an opposite direction into another extreme axial position when said terminal is being withdrawn from said opening.

Other more specific objects and advantages of the invention will become apparent when reference is made to the following description when considered in conjunction with the drawings wherein:

FIGURE l is a plan view of a partially formed blank 3,223,963 Patented Dec. 14, 1965 used in forming a detachable electrical connector in accordance with the invention;

FIGURE 2 is a side elevational view of the detachable connector with portions thereof broken away and in crosssection showing a spark plug terminal received therein;

FIGURE 3 is an end view of the ignition cable-receiving portion of the connector shown in FIGURE 2;

FIGURE 4 is an end View of the connector taken substantially on the plane of line 4-4 of FIGURE 2, with the spark plug removed;

FIGURE 5 is a side elevational view of one of the elements comprising the invention;

FIGURE 6 is a fragmentary end elevational of the element shown in FIGURE 5, looking in the direction of the arrow in FIGURE 5;

FIGURE 7 is a fragmentary cross-sectional View taken on line 7-7 of FIGURE 4 illustrating the relationships between the various elements comprising the invention and the spark plug terminal contained therein; and

FIGURES 8 and 9 are views similar to that of FIG- URE 7 but illustrating the position of the various elements during stages in the disengagement of the ignition cable terminal from the spark plug terminal.

Referring now in greater detail to the drawings, FIG- URE l illustrates a partially formed terminal or connector blank 10 which is subsequently formed to assume the configuration generally shown by FIGURES 2, 3 and 4.

The blank 10 may be formed of generally rectangular body portions 12 and 14 which are connected to each other by means of an integrally formed medial bridge or connecting portion 16 of relatively reduced width. Body portion 14 is preferably formed to have transversely directed corrugations or convolutions 18 which are provided with a plurality of indentations 20. Preferably, the indentations are formed in a plurality of substantially aligned rows but in staggered relationship as between successive rows.

Transverse ends 22 and 24 of body 12 are formed, as by notches or cut-out portions 26, to provide laterally extending and oppositely directed projections 28, 30 and 32, 34, respectively.

Blank 10 is subsequently curled, generally about its longitudinal axis 36, until body portion 14 assumes `a generally U-shape is illustrated by the end View thereof in FIGURE 3. Body portion 14 being thusly formed is suited for the later reception therein of one end of an ignition cable 38 shown in phantom lines in FIGURE 2. The upper ends 40 and 42 of the U-shaped body portion 14 are later curled inwardly toward each other, `as illustrated generally in phantom lines in FIGURE 3, in order to contain the ignition cable 38 therein and establish electrical contact therewith as, for example, by means of contacting an overcurled extension 37 of the electrical conductor or conductors therein. Cable 3S will, of course, as illustrated in FIGURE 2, assume the general form of the convolutions or corrugations 18.

Simultaneously with the forming of body 14 onto a U-shape, the medial connecting portion 16 and body portion 12 are also curled. The medial portion 16 is formed to assume a generally arcuate cross-section approaching a semi-circular configuration. Body portion 12, however, is spirally curled so as to form a generally cylindrical barrel or connecting portion 44 which is closely received about a spark plug terminal 46.

Prior to the curling operation described above, tabs or projections 28, 30, 32 and 34 could all be bent downwardly from the plane -of blank 10. During the curling of body portion 12, end portion 22 would be curled so as to pass under, or within, end 24. When the tabs 32 and 34 reached a position of general juxtaposition with slots 26 of end 22, tabs 32 and 34 would be bent generally inwardly toward the center of the spirally curled body por- 3 tion 12. As a result of the above, tabs 32 and 34 are bent in one direction while tabs 28 and 30 are bent in an opposite direction.

Consequently, the maximum size of aperture 48, as defined generally by the barrel-shaped body portion 12, is determined by the coaction of bent projections or tabs 32, 28 and 34, 30. That is, as the barrel 44 is urged radially outwardly, end portions 22 and 24 tend to .be moved relative to each other. However, because of the directions in which the tabs are bent, tabs 28 and 32 as Well as tabs 30 and 34 abut aganist each other to prevent undue expansion of the barrel aperture 48.

An aperture 50 formed through body portion 12 is adapted to receive therethrough a depression 52 of an arcuate spring clip or detent 54, shown in greater detail in FIGURES 5 and 6.

As shown in FIGURE 4, clip 54 is formed so as to frictionally engage a substantial portion of the outer peripheral surface of barrel 44. A portion of barrel 44, in FIGURE 4, is broken away and sectioned in order to better illustrate the manner in which projection 52 extends radially inwardly of the barrel through aperture or opening 50.

FIGURE 7 illustrates, in cross-section, the barrel 44 fully assembled into the spark plug terminal 46. As terminal 46 is urged into aperture 48, projection 52 is engaged by surface 56 of terminal 46 and moved, against the frictional forces encountered between the inner arcuate surface 58 of clip 54 and the outer perpheral surface of barrel 44, to the right until projection 52 engages the inner-most side of aperture 50. At this time further relative axial movement between clip 54 and barrel 44 is substantially prevented. However, further movement of terminal 46 causes projection 52 to slide upwardly along surface 56 (radially outwardly of barrel 44) until the larger diameter 60 is past porjec-tion 52, allowing the projection or detent portion 52 to move generally radially inwardly along surface 62. Relative axial movement of barrel 44 and terminal 46 continues until end surface 64 of barrel 44 abuts against the radial surface 66 of shoulder 68 formed on the spark plug. In view of the above, it should be apparent that opening or aperture 50 is of a length, generally axially of the barrel 44, sufiicient to permit substantial relative axial movement between clip 54 and barrel 44.

FIGURE 8 illustrates the barrel 44 in the process of being disconnected from the spark plug terminal 46. During withdrawal of terminal 46, clip 54, by virtue of projection 52 engaging surface 62, is moved relatively axially to the left of barrel 44 until projection 52 engages the outer-most side of opening 50. The size and location of projection 52 and opening 50 is :such as to result in end surface 64 being axially withdrawn to a point slightly beyond the larger piloting surface 70 of terminal 46.

As a consequence of the above, barrel 44 lmay be angularly displaced generally downwardly, as shown in FIG- URE 9, thereby causing expansion of the clip 54 and general radial outward movement of projection 52. Such angular movement permits the application of a substantially lesser disconnecting force to the barrel 44 than would otherwise be necessary if the barrel were to be withdrawn only axially of the terminal 46. The disconnection of the barrel 44 from the spark plug terminal 46 is then completed by merely cooking the barrel in a reverse angular direction or by merely applying a slight force on the barrel 44 in a direction generally axially of the terminal 46 while pivoting the barrel back into general alignment with the terminal 46.

Although but one form of the invention has been disclosed and described, it is apparent that other embodiments and modifications of the invention are possible within the scope of the appended claims.

We claim:

1. An electrical connector forming an electrical connection between an electrical cable and an electrical terminal member, comprising a first engaging portion formed to fixedly receive said cable therein, and `a second engaging portion connected to and spaced from said first engaging portion and adapted to detachably receive said terminal therein, :said second engaging portion comprising tirst and second curled portions the ends of which overlap each other to form a generally cylindrical barrel having a terminal-receiving opening therein for closely rcceiving said terminal, relatively movable positive abutment means provided on said first and second curled portions for preventing said opening from radially expanding to a size greater than a predetermined maximum size, and detent means frictionally mounted on said second engaging portion and movable relative thereto tending to move said abutment means away from each other, said detent means being adapted to be moved both radially and generally axially of said opening by said terminal whenever said terminal is moved into or out of operative engagement with said second engaging portion while maintaining sliding abutting contact with said terminal.

2. A detachable electrical connector for forming an electrical connection between first and second electrical terminals, comprising a first body portion adapted to be closed about said first terminal in a manner so as to securely engage said rst terminal, a generally cylindrical barrel connected to said first body portion and adapted for detachable connection with said second terminal, said barrel comprising a second body portion having ends curled in directions so as to have one of said ends overlaying the other of said ends thereby forming a generally cylindrical terminal-receiving opening, means formed on said second body portion near said ends for maintaining said overlaying relationship during periods in which said barrel is being connected with or disconnected from said second terminal, resilient means engaging a substantial portion of the outer surface of said barrel so as to urge said ends in a direction causing a reduction in the diametrical size of said terminal-receiving opening, an aperture formed through said second body portion, and detent means formed on said resilient means and projecting inwardly of said terminal-receiving opening through said aperture formed through said second body portion for engaging at least a portion of said second terminal whenever said barrel is connected to said second terminal, said detent means and said aperture being of such relative sizes as to permit the movement of said detent means axially of said cylindrical barrel by said second terminal whenever said barrel is moved axially along said second terminal.

3. A detachable electrical connector for forming an electrical connection between first and second electrical terminals, comprising a first body portion adapted to be closed about said first terminal so as to be securely engaged thereto, a curled second body portion forming a generally cylindrical terminal-receiving opening adapted for the reception therein of said second terminal and being connected to said first body portion, abutment means provided on said second body portion for limiting the degree to which said curled body portion can uncurl due to forces radially directed thereagainst and occasioned during periods in which said curled body portion is being connected with or disconnected from said second terminal, and detent means slidably mounted on said second body portion for abutably engaging said second terminal, said detent means being movable axially of said curled second body portion by said second terminal as said second terminal is moved axially Within said opening.

4. A detachable electrical connector for forming an electrical connection between an ignition cable and a spark plug terminal, comprising a generally U-shaped body portion adapted to be formed about said ignition cable in order to securely engage said cable, a spirally curled body portion having overlapping ends forming a terminalreceiving opening, a connecting portion of arcuate crosssection joining said curled body portion to said U-shaped body portion, a plurality of cut-out portions formed on said curled body portion near said ends, a plurality of tabs formed on said curled body portion near said ends, said tabs formed on the radially outermost overlapping end being bent through certain of said cut-out portions in a direction generally toward said terminal-receiving opening, said tabs formed on the radially innermost overlapping end being bent through other of said cut-out portions in a direction generally away from said terminalreceiving opening, a radially directed aperture formed in said spirally curled body portion, a relatively resilient member of arcuate cross-section friction'ally engaging a substantial portion of the radially outer surface of said spirally curled body portion, and a detent formed on said resilient member and extending through said aperture into said terminal-receiving opening, said detent and said aperture each being of such a length axially of said spirally curled body as to permit relative axial movement therebetween.

5. A detachable electrical connector for forming an electrical connection between an ignition cable and a spark plug having a generally cylindrical terminal provided with an annular recess formed therein axially inwardly of the ends thereof; comprising a body portion for securely engaging said ignition cable; a tubular terminal engaging portion connected to said body portion; said tubular portion defining a generally cylindrical opening, extending inwardly from an open end of said tubular portion, of a diametrical size sufficient to closely receive said terminal therein; an aperture formed through said tubular portion generally radially of said cylindrical opening; an arcuate member closely received by said tubular portion externally thereof; and a detent formed on said arcuate member and projecting through said aperture generally radially inwardly of said cylindrical opening; said detent having a length axially of said tubular portion substantially less than the axial length of said aperture so as to enable relative movement between said detent and said aperture; said detent being of a configuration adapted to be confined generally within said annular recess upon reception of said spark plug terminal within said cylindrical opening and being adapted to be moved by said annular recess axially within said aperture during withdrawal of said tenninal from said cylindrical opening until abutting contact is achieved between one axial end of said aperture and said detent; said aperture being so located axially of said tubular portion as to cause said end of said tubular portion to be in general radial juxtaposition with said annular recess when said abutting contact is achieved in order to permit angular deflection of said tubular portion with respect to said cylindrical terminal.

6. A detachable electrical connector for forming an electrical connection between an ignition cable and a spark plug having a generally cylindrical terminal provided with an annular recess formed therein axially inwardly of the ends thereof; comprising a body portion for securely engaging said ignition cable; a tubular terminal engaging portion connected to said body portion; said tubular portion deiining a generally cylindrical opening, extending inwardly from an open end of said tubular portion, of a diametrical size suflicient to closely receive said terminal therein; an aperture formed through said tubular portion generally radially of said cylindrical opening; an arcuate member closely received by said tubular portion externally thereof; and a detent formed on said arcuate member and received through said aperture movable relative to said aperture axially of said tubular portion; said detent being of a configuration adapted to be confined generally within said annular recess upon reception of said spark plug terminal within said cylindrical opening and being adapted to be moved by said annular recess axially within said aperture during withdrawal of said terminal from said cylindrical opening unit abutting contact is achieved between one axial end of said aperture and said detent; said aperture being so located axially of said tubular portion as to cause said end of said tubular portion to be in general radial juxtaposition with said annular recess when said abutting contact is achieved in order to permit angular deflection of said tubular portion with respect to said cylindrical terminal.

References Cited by the Examiner UNITED STATES PATENTS 1,603,679 10/ 1926 Gagnon.

1,821,443 9/1931 Mohr 339-258 X 2,380,908 7 1945 Heller 339-262 2,547,080 4/1951 Hebeler 339-273 X 2,559,174 7/1951 Skony 339-258 3,008,117 11/1961 Feustel et al 339-95 3,029,411 4/ 1962 Majewski 339-256 3,099,509 7/ 1963 Duenke 339-255 JOSEPH D. SEERS, Primary Examiner,

UNITED STATES PATENT oEFIcE CERTIFICATE OF CORRECTION Patent No. 3,223,963 December 14, 1965 Robert S. Rarey et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the grant, lines 2 to 4 for "assignors, by mesne assig:

ments, to General Motors Corporation, of Detroit, Michigan, a corporation of Delaware," read Said Rarey assignor to Chrysler Corporation, of Highland Park, Michigan, a corporation of Delaware, and said Johnson assignor to General Motors Corpor ation, of Detroit, Michigan, a corporation of Delaware, line 13, for "General Motors Corporation, its successors" read Chrysler Corporation and General Motors Corporation, their successors in the heading to the printed specification, lines 4 to 6, for "assignors, by mesne assignments, to General Motors Corporation, Detroit, Mich. a corporation of Delaware" read said Rarey assignor to Chrysler Corporation, Highland Park, Mich. a corporation of Delaware, and said Johnson assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware column 4, line 17, strike out "generally"; column 6, line 26, for "unit" read until Signed and sealed this 29th day of November 1966.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

3. A DETACHABLE ELECTRICAL CONNECTOR FOR FORMING AN ELECTRICAL CONNECTION BETWEEN FIRST AND SECOND ELECTRICAL TERMINALS, COMPRISING A FIRST BODY PORTION ADAPTED TO BE CLOSED ABOUT SAID FIRST TERMINAL SO AS TO BE SECURELY ENGAGED THERETO, A CURLED SECOND BODY PORTION FORMING A GENERALLY CYLINDRICAL TERMINAL-RECEIVING OPENING ADAPTED FOR THE RECEPTION THEREIN OF SAID SECOND TERMINAL AND BEING CONNECTED TO SAID FIRST BODY PORTION, ABUTMENT MEANS PROVIDED ON SAID SECOND BODY PORTION FOR LIMITING THE DEGREE TO WHICH SAID CURLED BODY PORTION CAN UNCURL DUE TO FORCES RADICALLY DIRECTED THEREAGAINST AND OCCASIONED DURING PERIODS IN WHICH SAID CURLED BODY PORTION IS BEING CONNECTED WITH OR DISCONNECTED FORM SAID SECOND TERMINAL, AND DETENT MEANS SLIDABLY MOUNTED ON SAID SECOND BODY PORTION FOR ABUTABLY ENGAGING SAID SECOND TERMINAL, SAID DETENT MEANS BEING MOVABLE AXIALLY OF SAID CURLED SECOND BODY PORTION BY SAID SECOND TERMINAL AS SAID SECOND TERMINAL IS MOVED AXIALLY WITHIN SAID OPENING. 